Dr. Universe: Why do we get phobias? -Ryan, 13, Hillarys, Western Australia

We all experience fear in our lives. It is a useful tool that helps humans and other animals survive. I happen to be afraid of dogs, thunderstorms, and water. But fears are quite different from phobias.

A phobia is an intense fear of an object or situation, often one that you actually don’t need to fear. It can create a lot of anxiety. It can cause your heart rate to speed up, make it hard to breathe, and trigger nervousness, vomiting, sweating, or dizziness.

Phobias usually fall into four groups. That’s what I found out from my friend Jake Zimmerman, who teaches abnormal psychology and is getting his Ph.D. at Washington State University.

One of the groups is animal phobias. This includes things like dogs, insects, and spiders. Another group is environmental phobias, like fear of heights, storms, and water. Body phobias include fear of things like getting shots or seeing blood. Finally, there are phobias related to situations like flying in an airplane, riding an elevator, or going to the dentist.

Just as there are many kinds of phobias, there are many reasons why someone might develop one. Zimmerman explained that a person’s chance of developing a phobia can sometimes be passed down from previous generations. Just as we get our hair color and eye color from information that’s passed down to us through our parents’ genetic code, we can also get a code that makes us more likely to develop intense anxiety or phobias.

Zimmerman added that phobias might develop from a person’s negative experience with an object or situation. For example, if you were bit by a dog, it could lead to a phobia. But a phobia may also come from observation—seeing something bad or scary happen to someone else or maybe even on the television.

A lot of people tend to have phobias about animals or nature. Your human ancestors really did have to watch out for poisonous snakes, spiders, and big animals with sharp teeth. An authentic sense of fear helped them survive.

“We are descendants of people who didn’t get too close to the edge,” Zimmerman says.

While some phobias are really intense, they can often be treated by slowly and repeatedly exposing people to the object they fear. Zimmerman said that for most people a phobia will develop pretty early in life—before age 15. It’s common to fear something when you are young and then eventually stop fearing it as you get older.

We‘ve come up with quite a long list of names for phobias. Basophobia is a fear of falling, mysophobia is the fear of germs, thalassophobia is fear of the ocean, cynophobia is the fear of dogs, and coulrophobia is the fear of clowns—just to name a few. Oh, and ailurophobia? That’s a fear of cats.